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Migraine is one of the most common neurologic disorders in children and adolescents. However, a quantitative comparison of multiple preventive pharmacologic treatments in the pediatric population is lacking.
Learn More >Occurrence, risk factors, and impact on daily life of chronic pain after critical illness have not been systematically studied.
Learn More >Osteoarthritis (OA) and pain are both made more severe by low-grade inflammation. We examined whether visceral fat, a major source of inflammatory cytokines and adipokines, was associated with an increased risk of knee OA or of musculoskeletal pain.
Learn More >Spinal cord injury (SCI) disrupts the communication between brain and body parts innervated from below-injury spinal segments, but rarely results in complete anatomical transection of the spinal cord. The aim of this study was to investigate residual somatosensory conduction in clinically complete SCI, to corroborate the concept of sensory discomplete SCI.
Learn More >The functional connectivity of the brain in chronic pancreatitis (CP) remains unknown. This study aimed to investigate functional connectivity in CP patients using resting state functional magnetic resonance imaging (fMRI) and explore the associations to clinical parameters and altered cerebral metabolites.
Learn More >Somatic symptom disorder (SSD) is characterized by a persistent and distressing psychological reaction to somatic symptoms. In pain disorders, the preoccupation with physical symptoms is associated with poor long-term outcomes. SSD may therefore be of use to identify and help chronic pain patients with particular needs.
Learn More >Vagal afferent sensory nerves, originating in jugular and nodose ganglia, are comprised of functionally distinct subsets whose activation evokes distinct thoracic and abdominal reflex responses. We used Cre-expressing mouse strains to identify specific vagal afferent populations and map their central projections within the brainstem. We show that Pirt is expressed in virtually all vagal afferents; whereas 5HT3 is expressed only in nodose neurons, with little expression in jugular neurons. TRPV1, the capsaicin receptor, is expressed in a subset of small nodose and jugular neurons. Tac1, the gene for tachykinins, is expressed predominantly in jugular neurons, some of which also express TRPV1. Vagal fibers project centrally to the nucleus tractus solitarius (nTS), paratrigeminal complex, area postrema and to a limited extent the dorsal motor nucleus of the vagus. nTS subnuclei preferentially receive projections by specific afferent subsets, with TRPV1+ fibers terminating in medial and dorsal regions predominantly caudal of obex, whereas TRPV1-negative fibers terminate in ventral and lateral regions throughout the rostral-caudal aspect of the medulla. Many vagal Tac1+ afferents (mostly derived from the jugular ganglion) terminate in the nTS. The paratrigeminal complex was the target of multiple vagal afferent subsets. Importantly, lung-specific TRPV1+ and Tac1+ afferent terminations were restricted to the caudal medial nTS, with no innervation of other medulla regions. In summary, this study identifies the specific medulla regions innervated by vagal afferent subsets. The distinct terminations provide a neuroanatomic substrate for the diverse range of reflexes initiated by vagal afferent activation. Vagal afferents transmit sensory information from visceral organs to the brainstem, where their activity alters sensation and visceral reflexes. Vagal afferents are comprised of distinct subsets which serve distinct functions. Little is known of the neuroanatomy of central projections of distinct vagal subsets, thus there remains an incomplete understanding of how visceral events evoke appropriate behavioral and reflex responses. This precludes rationally-developed pharmacological or electroceutical interventions to modify aberrant sensations/reflexes. Here, we used cell-specific reporter expression to identify the brainstem pathways of distinct vagal afferent subsets. We show that TRPV1+ vagal afferents innervate ipsilateral and contralateral dorsal/medial nTS subnuclei and the ipsilateral paratrigeminal complex, whereas TRPV1-negative vagal afferents innervate the ipsilateral rostral/ventral/lateral nTS subnuclei and the ipsilateral paratrigeminal complex.
Learn More >A variety of barriers ensures the protection of the peripheral nervous system from noxious blood-borne or surrounding stimuli. In this review, anatomy and functioning of the blood nerve barrier (BNB) and the blood DRG barrier (BDB) will be presented and key tight junction proteins described: ZO-1, claudin-1, -3, -5, -11, -12, -19, occludin, and tricellulin. Different diseases can lead to or be accompanied by nerve barrier disruption and impairment of nerve barriers worsens pathology. Peripheral nerve injury, diabetic neuropathy and inflammatory polyneuropathy cause an increased permeability of BNB and BDB. Knowledge and understanding of these mechanisms might ultimately lead to the invention of drugs to control barrier function to help ameliorating neurological diseases.
Learn More >Complex regional pain syndrome (CRPS) and fibromyalgia are chronic pain conditions of unexplained origins. In addition to symptoms in the diagnostic criteria, patients can report changes to vision and other sensations or bodily functions. It is unclear whether these are greater than would be expected due to normal ageing, living with chronic pain generally, or common co-morbidities of chronic pain such as depression or anxiety. We administered an on-line survey evaluating the frequencies and types of self-reported somatic symptoms, bodily changes, and sensory sensitivity in respondents with CRPS (n=390), fibromyalgia (n=425), and both CRPS and fibromyalgia ('CRPS+fibromyalgia'; n=88) compared to respondents with other chronic pain conditions (n=331) and pain-free controls (n=441). The survey assessed somatic symptoms (Patient Health Questionnaire-15), bodily changes, pain/discomfort/distress triggers, and pain intensifiers. We conducted ANCOVA's with age, sex, Patient Health Questionnaire-9 (measuring depression), Generalized Anxiety Disorder-7, pain duration in years, hours of pain per day, and number of pain-related medical diagnoses as covariates. After controlling for covariates, respondents with CRPS and/or fibromyalgia reported more somatic symptoms, changes in movement and biological responses, pain/discomfort/distress triggers, and pain intensifiers than pain(-free) control groups. Fibromyalgia specifically related to changes in vision and hearing; urinary/intestinal function; and drinking and eating. CRPS changes related to changes in hair, skin, and nails; and infection and healing. The CRPS+fibromyalgia group presented with features of both disorders with minimal additional stressors or symptoms over and above these. Our findings suggest CRPS and fibromyalgia share underlying pathophysiologies, although specific mechanisms might be different.
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